The Impact of Truth Surrogate Variance on Quality Assessment/Assurance in Wind Tunnel Testing

Wind tunnel testing and computational fluid dynamics in FLNG and floating production system design

The APPEA Journal ◽

10.1071/aj15119 ◽

2016 ◽

Vol 56 (2) ◽

pp. 613

Author(s):

Johnathan Green ◽

Subajan Sivandran

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Wind Tunnel ◽

Numerical Modelling ◽

Full Range ◽

Wind Tunnel Testing ◽

Advantages And Disadvantages ◽

Time Histories ◽

The Impact ◽

Tunnel Testing

Demonstrating how numerical modelling, such as computational fluid dynamics (CFD), can be used to validate results from detailed physical wind tunnel models of FLNG vessels and floating systems is the objective of this extended abstract. 3D rapid prototyping is used to build detailed physical wind tunnel models. This physical model (normally of an approximate scale of 1:200) is then placed in a wind tunnel facility to measure the time histories of the wind loads for a full range of wind directions and a range of drafts. CFD is then used to validate the wind tunnel modelling results. Numerical modelling can also be used to analyse a number of different issues such as the impact of turbine exhaust dispersion, and turbulence on helicopter operations and resulting helideck availability. This extended abstract discusses the importance of wind tunnel testing and numerical modelling during the design phase. The idea that numerical modelling does not replace pure theoretical or experimental results, but acts to complement them with gaining a greater overall picture, will be highlighted. Findings will be presented to discuss the advantages and disadvantages of both approaches, and highlight results such as wind shear and turbulence impacts being best calculated through wind tunnel testing. The extended abstract demonstrates that, ideally during the design process, wind tunnel testing should be followed by numerical modelling to interpolate results.

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Effects of Topside Structures and Wind Profile on Wind Tunnel Testing of FPSO Vessel Models

Journal of Marine Science and Engineering ◽

10.3390/jmse8060422 ◽

2020 ◽

Vol 8 (6) ◽

pp. 422

Author(s):

Seungho Lee ◽

Sanghun Lee ◽

Soon-Duck Kwon

Keyword(s):

Wind Tunnel ◽

Operating Mode ◽

Wind Loads ◽

Wind Tunnel Testing ◽

Wind Speeds ◽

Medium Level ◽

Wind Profiles ◽

The Impact ◽

Gantry Cranes ◽

Tunnel Testing

This study examined the effects of wind loads on a floating production storage and offloading (FPSO) vessel, focusing in particular on the impact of the turbulent wind profiles, the level of details of the topside structures, and the operation modes of the gantry cranes. A series of wind tunnel tests were performed on the FPSO vessel model, developed with a scale of 1:200. It was observed that the wind loads measured using a low-detail model were often greater than those measured using a high-detail model. The measured wind loads corresponding to the Norwegian Maritime Directorate (NMD) profile with an exponent of 0.14, were approximately 19% greater than those corresponding to the Frøya profile in the entire range of wind directions, because of the slightly higher mean wind speeds of the NMD profile. The wind forces increased by up to 8.6% when the cranes were at operating mode compared to when they were at parking mode. In view of the observations made regarding the detail level of the tested models, a medium-level detail FPSO model can be considered adequate for the wind tunnel testing if a high-detail model is not available.

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